NON Catholic argument:
But our rebirth is spiritual, and Mary only gave birth to Jesus in the flesh. Jesus does not communicate to us the physical life which He derived from Mary.
Catholic response:
This smacks of Gnosticism, an early heresy which denied the Incarnation and hoped for a purely spiritual salvation. The Bible, on the other hand, clearly teaches that our salvation is both physical and spiritual by virtue of Jesus’ Incarnation.
Human beings are both physical and spiritual, a body and a soul. Our Lord assumed our human nature - both a human body and a human soul - in order to save us. The Incarnation actually made the Atonement possible; Jesus’ physical Blood has redeemed us (Eph 1:7, Col 1:14, Heb 9:12, 1 Pet 1:2, 1 Jn 1:7, Rev 5:9), His bodily wounds and sufferings have redeemed us: “By his bruises we are healed” (Is 53:5).
Jesus actually saves us by uniting us to His own Humanity! Thus the Bible says that the redeemed are members of His Body (Ephesians 5:29-32), and that our bodies are members of Christ (I Corinthians 6:15). We are truly united to Jesus’ glorified human Body, which is the same exact Body which He drew from Mary, and in which He suffered and died (as He proved by the scars in his hands, feet and side: Luke 24:39-40; John 20:20, 27).
We even bear His resurrection life within our very bodies until the Last Day, when Jesus will finally redeem and glorify our bodies (John 6:54; Rom 8:23 Phil 3:21). Our Redemption is not a purely “spiritual” reality; it most definitely has a physical aspect as well.
The Incarnation is inseparable from the Redemption. We receive life from Christ through His Sacred Humanity, which He received from Mary! So Jesus’ Mother is our Mother as well, for He drew from her the same flesh to which we are united in the Body of Christ